/Engine/Source/Editor/CurveEditor/Public/Tree/CurveEditorTree.h
Retrieve an item from its ID, assuming it is definitely valid
[FCurveEditorTreeItem](API\Editor\CurveEditor\Tree\FCurveEditorTreeItem) & GetItem ( [FCurveEditorTreeItemID](API\Editor\CurveEditor\FCurveEditorTreeItemID) ItemID )